Finnex THD-700S 700 W Titanium Heater Element

Exact-model photograph is not verified. Text-only reference. The official THD family image is shared across three wattage options and does not identify the selected 700 W assembly or package; the exact-model photo gap remains open.

Finnex lists the THD-700S at 700 W, 120 V and 7.3 A, with a 0.74-inch diameter, 13.75-inch tube and a 110–200 US-gallon band. The lower endpoint matters, but the finder cannot enforce it; the Shop identifies an element-only option with the controller sold separately. This is an identification reference, not a tank-fit match.

Search results may include other models. Confirm the exact model, applicable region, condition and included parts before ordering.

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Documented model details

• Finnex’s exact THD-700S family row lists 700 W, 120 V, 7.3 A, a 0.74-inch diameter, 13.75-inch length and a 110–200 US-gallon capacity band. Voltage and amperage appear in separate columns; the page does not state the current’s reference condition or a frequency.
• The published band has both a 110-gallon floor and a 200-gallon ceiling. It is a manufacturer sizing range, not a guarantee of temperature performance in every room or installation; the lower boundary cannot be represented by this finder’s maximum-only volume rule.
• The same family table distinguishes THD-700S from THD-500S (500 W, 12.5 inches, 70–125 gallons) and the separate TH-800S (800 W, 16.5 inches, 140–265 gallons). The shared table does not make these elements interchangeable.
• Finnex describes THD as a titanium element with an internal quartz sleeve and says the TH/THD units include a protective guard. Its broader family copy names freshwater and marine use. These descriptions are not a shatterproof certification, independent durability test or installation direction.
• The official Shop variant data identifies a 700 Watt selection as SKU “THD-700s” and Shopify variant 51093135753515, with an empty barcode field. The Shop description says “Heating Element Only” and that controllers are sold separately; the variant ID is not a UPC.
• The captured one-page manufacturer instructions index lists HMH, HMS and HPC heater manuals, but not THD. It is a limited search of that index, not proof that a separate THD instruction document is unavailable.
• The official THD gallery image is shared across 300 W, 500 W and 700 W selections and shows only a guarded tube with a COMPACT label. It does not identify the selected wattage, model, package or scale.

Limits to weigh

• The matcher cannot require the stated 110-gallon minimum, so the model remains reference-only and is not a fit recommendation for a tank merely because it is under 200 gallons.
• The Shop says the item is an element only and controllers are sold separately. The reviewed source set does not identify a specific compatible controller, its load limits or setting range, or a complete THD operating arrangement.
• The family table reports 120 V and 7.3 A without an explicit amperage reference condition and gives no frequency. Those values are not a complete nameplate or proof of electrical compatibility.
• The reviewed instruction index does not provide THD-700S installation directions. Immersion depth, orientation, clearances, dry-operation permission and inline use remain unresolved; a guard or controller requirement does not answer them.
• No exact THD-700S wattage/package image was verified. The saved official family visual is not used as an exact selected assembly or package image in this text-only lookup.
• The exact Amazon.com US search attempt returned HTTP 503 before any listing identity or package could be inspected. This is not evidence that a listing is absent; no ASIN or sibling model is substituted.

Check before ordering

• Check the offered model label and package for Finnex THD-700S / 700 W and, where shown, Shop SKU THD-700s. Do not confuse it with THD-500S, THD-300S or TH-800S, and do not treat the variant ID as a UPC.
• Account for Finnex’s stated 110–200 US-gallon band, including its 110-gallon minimum; do not infer that every tank at or below 200 gallons is a fit or treat the rating as a heat-performance guarantee.
• Confirm which external controller is supplied, if any, and independently verify its compatibility and load limits for the exact element. The reviewed Shop record describes the element alone and does not establish a complete controller package or setting range.
• Read the exact element and controller nameplates and their instructions before installation. The manufacturer table’s 120 V and 7.3 A row does not state frequency or the amperage reference condition, and the reviewed index did not list a THD manual.
• Measure the 13.75-inch tube and 0.74-inch diameter against the intended space, then confirm required clearance, immersion and mounting from the instructions for the actual element/controller combination; the reviewed family table does not specify those conditions.
• Treat the buying route as a Finnex THD-700S full-model search, not an exact listing promise. Verify model and package on the destination rather than accepting a THD-500S, TH-800S or another close result.