The 300mm External Coupler (Female Coupler) is part of our SpiraSafe range although this coupler doesn't have the rubber gaskets as it is generally used for joining fittings together.
The diameter of this coupler matches the diameter of spiral tube so a fitting will fit inside the coupler.
Please note: To purchase this product we require a valid F-GAS number, however we do not have one on record for your account. Please contact our Customer Experience team on 01206 864467 for support with this.