.5" For 1.5" pvc pipe fittingsFits hole size 2 3/8" - 2 3/4"Use glass hole saw 2 1/2" Connection: 1.5" Slip x 1.5" Slip or 1.5" FPT x 1.5" FPTPlastic bulkhead fittings should be used any time a hole is made through glass or acrylic to simplify the attachment of plumbing pieces. The use of a Plastic bulkhead fitting will help ward off stress cracks and leakage.

• Glass Construction — Constructed from glass — carefully selected for durability, safety, and long-term performance in your pet's environment.
• No Assembly Required — Ready to use straight out of the packaging — no tools, no complicated setup, just immediate use.
• Perfect for All Aquariums — Thoughtfully designed to meet the specific needs of all aquariums — a product that genuinely understands your pet.
• Built to Last — Premium materials and quality construction ensure lasting performance and durability through everyday use.
• Great Value — Exceptional quality at a competitive price — everything your pet needs without unnecessary compromise.