Affordable Pet Doors Melbourne install two brands of pet doors for security screen doors that are ideal for cats:
Petway Pet Doors – made from a sturdy UV Resistant thermoplastic
Pig In Mud Pet Doors – made from tempered aluminium alloy (slightly more expensive)
Petway Small Pet Door – $220 including supply and installation
Dimensions: 
- Flap Size: 24cm x 19cm
- Suitable for cats and small dogs
Features:
- Draught-proof and transparent flap
- 4-way locking mechanism: Door Open / Door Locked / In Only / Out Only
- Available in White, Brown and Primrose
- Made from UV Resistant thermoplastic
(Yarra Valley / Mornington Peninsula – an additional $40 travel surcharge applies)
Pig In Mud Medium Security Screen Door – $260 including supply and installation
Dimensions:
- Flap Size: 17.8m x 28.6cm
- Suitable for cats and small dogs
Features:
- Impact-resistant frame made of tempered aluminium alloy.
- Lockout Slide included to keep pet(s) in or out
- Transparent polyvinyl flap lets pet see when lockout slide is in place; secures w/magnetic strip
- Floating bottom sill ensures perfect seal
- Made from tempered aluminium alloy
(Yarra Valley / Mornington Peninsula – an additional $40 travel surcharge applies)